Anti-government gunmen occupying a police station in Yerevan released three hostages on Monday on the second day of their standoff with Armenian security forces.

Armenia’s police and National Security Service (NSS) said one of the freed individuals is a police officer while the other an ambulance driver. Their release was the result of continuing negotiations, said the two law-enforcement agencies.

General Hunan Poghosian, the first deputy chief of the national police, told reporters that five other policemen are still being held hostage inside the building that was seized on Sunday morning by a dozen or so armed men affiliated with a radical opposition group.

Another policeman was set free later in the day, according to the NSS. The latter also said that the hostage takers and the officers held by them have been provided with food and medication.

Among the remaining hostages were General Vartan Yeghiazarian, another deputy police chief, and Colonel Valeri Osipian, a deputy head of Yerevan’s police department. Another police colonel, Artur Vanoyan, was killed when the gunmen stormed the police compound located in the city’s southern Erebuni district.

The hostage takers are demanding the release of Zhirayr Sefilian, the leader of their Founding Parliament opposition movement arrested last month for allegedly plotting an armed revolt. They also want President Serzh Sarkisian to step down.

Poghosian again rejected those demands. He reiterated police calls for the attackers to free the remaining hostages and give themselves up. Law-enforcement bodies are legally empowered to use force against them, he warned.

Armenia - General Hunan Poghosian, the first deputy chief of the Armenian police, speaks to reporters near a police building in Yerevan seized by anti-government gunmen, 18Jul2016.

The NSS echoed that warning in stronger terms, branding the attackers “terrorists” that “pose a threat to not only the hostages but also the public.”

It said that despite the release of the three hostages it cannot exclude a “tragic” end to the crisis.

“The terrorists must realize that they have no alternative to unconditionally fulfilling the authorities’ demands as soon as possible,” the powerful security service said in a statement. “Armenian law-enforcement bodies still hope that the members of the armed group will only be guided by prudence when making decisions.”

The NSS and the police continued to cordon off the area and block Erebuni roads leading to it. Scores of police officers, interior troops and NSS personnel remained deployed there as of Monday afternoon.

Varuzhan Avetisian, one of the leaders of the gunmen, told Aravot.am by phone that they freed the two hostages at Sefilian’s request which he said was communicated to them by another Founding Parliament member allowed to visit them.

Avetisian claimed that Sefilian also proposed a compromise solution to the hostage crisis. “I can’t publicize it,” he said. “Negotiations, discussions are underway, let’s see what happens.”

Poghosian declined to confirm Sefilian’s involvement in the negotiations. But he did say that the Armenian authorities are ready to reciprocate “adequate steps” by the hostage takers.

Sefilian was arrested on June 20 less than two weeks after announcing plans to set up a new opposition movement that would strive topple the government “with the help of the people and the army.”

Armenia - Zhirayr Sefilian (L) and another arrested leader of the Founding Parliament movement are taken to the Investigative Committee for further questioning, Yerevan, 9Apr2015.

According to Armenia’ Investigative Committee, Sefilian and six other men arrested last month acquired large amounts of weapons with the aim of seizing government buildings and a television tower in Yerevan. Sefilian and Founding Parliament deny the charges, saying that he is prosecuted only because of his strong opposition to Armenian territorial concessions to Azerbaijan allegedly planned by Sarkisian.

Founding Parliament tried unsuccessfully to achieve regime change through peaceful rallies last December after teaming up with several other small opposition groups. Their alliance called the New Armenia Public Salvation Front attracted only several hundred people to those protests.

A hardline nationalist born and raised in Lebanon, Sefilian was a prominent field commander during the 1991-1994 war in Karabakh. He has campaigned against both Sarkisian and former President Robert Kocharian over the past decade.

In 2006, Sefilian was arrested and subsequently sentenced to 18 months in prison for allegedly attempting to mount an armed uprising against the Kocharian government. He denied the accusations as politically motivated.

The 48-year-old was again detained and spent a month in jail last year ahead of a series of anti-government protests planned by Founding Parliament during official ceremonies to mark the 100th anniversary of the Armenian genocide in Ottoman Turkey. Sefilian’s group had urged Armenians to use the genocide centennial to bring down the Sarkisian government.